The sea of galaxies comes slowly into view

"We are talking about massive galaxies, twice as massive as the Milky
Way today," said Karina Caputi, an astronomer at University of Groningen
in the Netherlands and lead author on the new work. "Currently, even the
most up-to-date galaxy-formation models cannot predict such massive
galaxies [before] almost 2 billion years after the Big Bang,"

http://www.space.com/31163-monster-g...cientists.html

Photo
http://cdn.eso.org/images/large/eso1545a.jpg

ESO press release
http://www.eso.org/public/news/eso1545/

Scientific Article
http://www.eso.org/public/archives/r...5/eso1545a.pdf
That article says (page 16)
"Our results indicate that some very massive galaxies are
present since the universe was only a billion years old."

The milky way is more than 10Gy old. How a galaxy TWICE AS MASSIVE can
appear in just 945My (z=6) ??

And the authors say that many more galaxies even more massive are
lurking behind, obscured by dust. This confirms what I have reported
here in a previous discussion: the sea of galaxies waiting for us behind
the farthest galaxies that we can see now.

Current cosmology (big bang theory) is coming to an end.

In article , jacobnavia
writes:

The milky way is more than 10Gy old. How a galaxy TWICE AS MASSIVE can
appear in just 945My (z=6) ??

And the authors say that many more galaxies even more massive are
lurking behind, obscured by dust. This confirms what I have reported
here in a previous discussion: the sea of galaxies waiting for us behind
the farthest galaxies that we can see now.

Current cosmology (big bang theory) is coming to an end.

If I go into a cafe and see three people more than 2 metres tall, I
would be surprised. If I surveyed all the people in a large country, I
wouldn't be. The larger the sample, the more we should expect atypical
members of the sample. Check out papers by Peter Coles and Ian Harrison
using extreme-value statistics. They debunk many claims that extremely
large objects somehow contradict established theory. (Interestingly,
Stuart Coles (no relation, as far as I know) at the University of
Bristol has written a book on statistical modeling of extreme values.)

On Sunday, November 22, 2015 at 2:38:31 PM UTC-5, Phillip Helbig (undress to reply) wrote:


If I go into a cafe and see three people more than 2 metres tall, I
would be surprised. If I surveyed all the people in a large country, I
wouldn't be. The larger the sample, the more we should expect atypical
members of the sample. Check out papers by Peter Coles and Ian Harrison
using extreme-value statistics. They debunk many claims that extremely
large objects somehow contradict established theory. (Interestingly,
Stuart Coles (no relation, as far as I know) at the University of
Bristol has written a book on statistical modeling of extreme values.)

------------------------------------------------------

But say there is an unexplored island and conventional theory
predicts that because of its likely environmental conditions,
probable food resources and isolation, the inhabitants should be
pygmies.

Then the island is explored for the first time and numerous people
over 2 meters tall are there to greet the explorers.

One could not hide behind crude statistical arguments based on
faulty assumptions, but would have to admit that theory got it
wrong.

RLO
Fractal Cosmology

In article ,
"Robert L. Oldershaw" writes:

If I go into a cafe and see three people more than 2 metres tall, I
would be surprised. If I surveyed all the people in a large country, I
wouldn't be. The larger the sample, the more we should expect atypical
members of the sample. Check out papers by Peter Coles and Ian Harrison
using extreme-value statistics. They debunk many claims that extremely
large objects somehow contradict established theory. (Interestingly,
Stuart Coles (no relation, as far as I know) at the University of
Bristol has written a book on statistical modeling of extreme values.)

------------------------------------------------------

But say there is an unexplored island and conventional theory
predicts that because of its likely environmental conditions,
probable food resources and isolation, the inhabitants should be
pygmies.

Then the island is explored for the first time and numerous people
over 2 meters tall are there to greet the explorers.

One could not hide behind crude statistical arguments based on
faulty assumptions, but would have to admit that theory got it
wrong.

The question is which scenario corresponds best to high-redshift
galaxies. Certainly many "surprising" claims have been made in the
literature, but, as I mentioned, some have been debunked. Since no-one
has debunked the debunking, it stands, even if those debunked don't
loudly admit it.

On Monday, November 23, 2015 at 11:58:47 PM UTC-5, Phillip Helbig (undress =
to reply) wrote:

=20
The question is which scenario corresponds best to high-redshift=20
galaxies. Certainly many "surprising" claims have been made in the=20
literature, but, as I mentioned, some have been debunked. Since no-one=20
has debunked the debunking, it stands, even if those debunked don't=20
loudly admit it.

Are you referring to "surprising" claims made within the context
of conventional cosmology (i.e., the discovery of gravitational
waves, various failed dark matter predictions, various predicted
turnovers to "homogeneity" at less than 100 Mpc, etc) that have
been convincingly debunked. Or are these problems not on your radar?

RLO
Fractal Cosmology

In article ,
"Robert L. Oldershaw" writes:

The question is which scenario corresponds best to high-redshift=20
galaxies. Certainly many "surprising" claims have been made in the=20
literature, but, as I mentioned, some have been debunked. Since no-one=20
has debunked the debunking, it stands, even if those debunked don't=20
loudly admit it.

Are you referring to "surprising" claims made within the context
of conventional cosmology (i.e., the discovery of gravitational
waves, various failed dark matter predictions, various predicted
turnovers to "homogeneity" at less than 100 Mpc, etc) that have
been convincingly debunked. Or are these problems not on your radar?

No. A non-detection is not a surprise unless there is a REALLY FIRM
prediction. That's not the case with gravitational waves. I guess you
mean "non-discovery", since they haven't been directly detected and if
they had been, that wouldn't have been a surprise. (That they exist is
a firm prediction, but at what amplitude in what frequency range is
not.) Dark matter is a firm prediction, but not the specific qualities.
Homogeneity? Look at the CMB. It's pretty homogeneous, so it is
obvious that there is a turnover at some scale. Apart from a handful of
people who have been saying that the large-scale structure is fractal on
all observable scales for the last 30 years or so, whatever the
observational data, everyone is convinced that there is a turnover.

[[Mod. note -- There actually are a few "really firm" predictions
of gravitational waves with amplitudes and frequencies already tightly
constrained from other astronomical observations, namely various binary
stars. In fact, the gravitational-wave predictions for some of these
are sufficiently firm that it is planned to use these as test sources
to verify that the (proposed) LISA space-based gravitational-wave
detector is working correctly.

See
Stroerr and Vecchio,
"The LISA verification binaries",
Classical & Quantum Gravity 23 (2006), S809
http://dx.doi.org/10.1088/0264-9381/23/19/S19
astro-ph/0605227
-- jt]]

Le 22/11/2015 20:38, Phillip Helbig (undress to reply) a écrit :
If I go into a cafe and see three people more than 2 metres tall, I
would be surprised. If I surveyed all the people in a large country, I
wouldn't be.

Mr Helbig

At time t = 956 My after the supposed big bang, ALL galaxies are BABY
galaxies. They can't have more than 700-750My, if I follow SOME logic.

First stars can form only about 180My after the "bang" since we must
wait until the CMB drops around 50kelvins.

Yes, I know about statistics, but how can a galaxy in only 750My grow
from zero to TWICE the Milky Way???

Yes, if you measure the height of all babies in earth you are bound to
find exceptionally big babies but... what would you say if you found a
baby of 3.4m height???

Statistical fluke?

No, you would say: This is not a baby!

There are LIMITS imposed on the growth of galaxies by physical laws that
make galaxies of just 750My and that enormous size IMPOSSIBLE you see?

jacob

[[Mod. note -- Physical laws do indeed place limits on how fast galaxies
can form and grow. If we had solid and well-validated theoretical models
of galaxy formation/growth we could probably compute those limits.

But I don't think we have this level of understanding (yet). We sort
understand the main ingredients that go into galaxy formation/growth,
but I don't think we know all the parameters (density? temperature?
pressure? chemical composition? magnetic fields? turbulence? ambient
generation-I stellar population environment?) well enough to put
reliable limits on just how fast/slow formation and growth occur.
Nor do we have good observational data (yet) on very young galaxies
to help constrain these theoretical models.

So how do we know that 750 My isn't enough time?
-- jt]]

In article , jacobnavia
writes:

Yes, I know about statistics, but how can a galaxy in only 750My grow
from zero to TWICE the Milky Way???

There are LIMITS imposed on the growth of galaxies by physical laws that
make galaxies of just 750My and that enormous size IMPOSSIBLE you see?

[[Mod. note -- Physical laws do indeed place limits on how fast galaxies
can form and grow. If we had solid and well-validated theoretical models
of galaxy formation/growth we could probably compute those limits.

But I don't think we have this level of understanding (yet).

So how do we know that 750 My isn't enough time?

Indeed. AFAIK, the IMF is not derivable from first principles; it has
to be put in "by hand". And this is something pretty basic.

On Monday, November 23, 2015 at 11:59:13 PM UTC-5, Phillip Helbig (undress to reply) wrote:


Indeed. AFAIK, the IMF is not derivable from first principles; it has
to be put in "by hand". And this is something pretty basic.

Quite true! And you can include most of the early observable universe
modeling, as well as ab initio galaxy formation, in the "put in by
hand" category.

RLO
Fractal Cosmology

On 11/23/15 12:37 PM, jacobnavia wrote:
Le 22/11/2015 20:38, Phillip Helbig (undress to reply) a ecrit :
If I go into a cafe and see three people more than 2 metres tall, I
would be surprised. If I surveyed all the people in a large country, I
wouldn't be.


There are LIMITS imposed on the growth of galaxies by physical laws that
make galaxies of just 750My and that enormous size IMPOSSIBLE you see?

jacob

[[Mod. note -- Physical laws do indeed place limits on how fast galaxies
can form and grow. If we had solid and well-validated theoretical models
of galaxy formation/growth we could probably compute those limits.

But I don't think we have this level of understanding (yet). We sort
understand the main ingredients that go into galaxy formation/growth,
but I don't think we know all the parameters (density? temperature?
pressure? chemical composition? magnetic fields? turbulence? ambient
generation-I stellar population environment?) well enough to put
reliable limits on just how fast/slow formation and growth occur.
Nor do we have good observational data (yet) on very young galaxies
to help constrain these theoretical models.

So how do we know that 750 My isn't enough time?
-- jt]]

Based on theoretical, laboratory and industrial experience
the most unknown contributor to galactic formation
is surely "turbulence?".
The Navier Stokes equations describing this viscous contribution
have never been solved.
"The Clay Mathematics Institute has called
Navier--Stokes existence and smoothness
one of the seven most important open problems
in mathematics and has offered a US$1,000,000 prize
for a solution or a counter-example."
RDS


[[Mod. note -- Not to disagree with anything the poster wrote, but
note that in *some* (not all) contexts, we can model the large-scale
effects of turbulence quite well. For example, models of stellar
structure for solar-type stars include a large (turbulent) "convection
zone". For the sun these models agree very nicely with the measured
speed of sound determined from helioseismology. (To answer a frequent
concern addressed in other discussions, I think the number of measured
helioseismology speed-of-sound data points is much larger than the
number of free parameters in the solar models.)
-- jt]]